1. Field of the Invention
The present invention relates to a data processing method, a data processing apparatus, an information recording medium, and a computer program. More specifically, the present invention relates to a data processing method, a data processing apparatus, an information recording medium, and a computer program that, in a content reproduction processing of performing a parallel reproduction of image data and audio data that are contained in different locations of a disc, enable a seamless content reproduction through a prevention of a discontinuity in reproduction caused by a jump processing that occurs in a processing of switching and reading each of the image data and the audio data.
2. Description of Related Art
A recording media including a disc such as a Blu-ray disc obtained by an application of a blue laser or a DVD (Digital Versatile Disc) may contain various software data such as audio data of music etc., image data of movies etc., game programs, and various application programs etc.
There is provided a prescription of data storage formats corresponding to these various data, allowing each data to be stored in conformity with the format of each data.
A consecutive reproduction (a so-called slide show) of a still image is available as one of data reproduction modes. Each still image signal is encoded into an intra-frame encoded image (I-picture) of a MPEG2 (Moving Picture Experts Group 2) video and is multiplexed with a MPEG2 transport stream. Further, a multiplexing of the I-picture, an audio and a sub picture with the MPEG2 transport stream makes it possible to reproduce the audio and the sub picture in synchronization with the slide show. The above slide show is supposed to provide, on the basis of a PTS (Presentation Time Stamp) set as attribute information corresponding to data as time information of a reproduction timing, a reproduction that conforms to a prescribed timing.
To reproduce the audio in parallel with the consecutive reproduction (a browsable slide show) of the still image in a configuration of allowing the image data and the audio data to be individually stored in the disc, it becomes necessary to perform a processing that conforms to a prescribed sequence that the image data and the audio data are alternately read from the disc, and the read data of each of the image data and the audio data is stored in a buffer and is then outputted through a processing of decoding the data.
The processing of reading and reproducing the content stored in the disc follows procedure steps of an acquisition of information from the disc, a temporary storing (buffering) of acquired information, a decoding of buffer data, and an output of decoded data.
The decoding of the buffer data involves a processing such as the decoding of MPEG data if the contents are in the form of the MPEG data, or the decoding of encrypted data if the encrypted data is given, for instance.
In a case where the image data and the audio data are stored individually in the disc, with each data located apart, seeking of a read head, that is, a jump processing is required. The jump processing, if occurs, requires a period of time between the processing of jumping to a position away from a certain data reproduction position of the disc and the processing of reading and reproducing the data from a next read position, in which case, an increase of the above period of time often leads to an occurrence of discontinuity in reproduction.
Thus, in a case of reading and reproducing the audio in parallel with an execution of the consecutive reproduction (the browsable slide show) of the still image as described above, a configuration of performing an alternate reading of the image data and the audio data along with the jump processing has a problem of causing the discontinuity of reproduced data if the time required for the jump processing is increased.